Rotary member with safety mechanism

ABSTRACT

A gantry of a tomography apparatus has a rotary member that is rotatable around an axis. The rotary member carries at least one component attached to the outside thereto. The component is attached by primary and secondary attachment mechanisms, with only the primary attachment mechanism engaged during normal operation. The secondary attachment mechanism, a T-slot interface in one embodiment, engages for safety and other reasons when the primary attachment mechanism is not functioning properly.

BACKGROUND

The subject matter disclosed herein relates generally to gantry designand, more particularly, safety mechanisms for gantries.

Gantries are an important part of radiography and tomography systems. Amedical imaging system can include a gantry comprising a stationaryframe for supporting a rotary member about a scanning axis of thescanner. The rotary member includes a central opening large enough toreceive a patient extending along the scanning axis. The rotary memberis rotated about a patient during a scanning or imaging procedure. Anx-ray tube can be positioned on the rotary member diametrically acrossthe central opening from an array of x-ray detectors. As the rotarymember rotates, the x-ray tube projects a beam of energy, or x-rays,along a scan plane, through a patient, and to the detector array. Byrotating the x-ray source about the scanning axis and relative to thepatient, x-rays are projected through a patient from many differentdirections. An image of the scanned portion of a patient can beconstructed from data provided by the detector array using a computer.

X-ray detectors, x-ray tubes, and other components can be attached tothe rotary member. These components can be heavy, and the rotary membercan be rotated at high speeds. This can create substantial force.Fastening elements attaching the components to the rotary member can besubjected to particularly high stress, especially as the speed ofrotation increases. Fastening elements may not be set properly by atechnician or installation professional. Fastening elements may bend,break, and/or cause a component to detach from the rotary member. Thesefactors can lead to damage to the radiography or tomography system orendangerment of personnel in its vicinity. A secondary source ofattachment is useful for safety and usability.

BRIEF DESCRIPTION

In accordance with an embodiment, a gantry for a tomography system isprovided that can comprise a stationary support structure, a rotarymember with an opening for insertion of a subject, wherein the rotarymember is attached to the support structure, a component, wherein thecomponent can be attached to the rotary member by a primary attachmentmechanism, and wherein the component can be attached to the rotarymember by a secondary attachment mechanism, the secondary attachmentmechanism being a T-slot interface. Further, the system can include asocket securable to a first member and having a base defining a recessbordered by a lip, a fastener having an elongate stem portion securableto a second member and a head slidably insertable into the recess of thesocket where it is retained by the lip of the socket, and wherein thefirst member is the rotary member and the second member is thecomponent, or the first member is the component and the second member isthe rotary member. Further, the system can include a latch for securinga t-slot fastener in place to prevent axial movement of the fastenerfrom a t-slot socket, wherein the t-slot fastener includes an anglededge on an insertion side, and the angled edge depresses the latch asthe t-slot fastener is slid into the t-slot socket.

In one embodiment, during rotation of the rotary member, the secondaryattachment mechanism does not support the weight of the component if theprimary attachment mechanism is engaged. If the primary attachmentmechanism is not engaged, the secondary attachment mechanism supportsthe weight of the component. In this case, the t-slot interface cangenerate a human-audible noise. The secondary attachment mechanism cansupport partial or full weight of the mechanism if the primaryattachment mechanism is weak, faulty, broken, or only partially engaged.

In accordance with an embodiment, a component is provided, including atleast one receiving slot to accept a primary attachment mechanism, atleast one t-slot fastener as part of a secondary attachment mechanism,and wherein the primary and secondary attachment mechanisms can be usedto attach the component to a support structure.

In accordance with an embodiment, a support structure is provided,including at least one receiving slot to accept a primary attachmentmechanism, at least one receiving socket as part of a secondaryattachment mechanism, the socket having a base defining a recessbordered by a lip, wherein the primary and secondary attachmentmechanisms can be used to attach a component to the support structure.The secondary attachment mechanism does not support the weight of thecomponent if the primary attachment mechanism is engaged.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an angled view of a medical imaging system with a gantry inaccordance with an embodiment.

FIG. 2 is a block schematic diagram of a medical imaging system inaccordance with an embodiment.

FIG. 3 is a side view of a component attached to a rotary member withprimary and secondary attachment mechanisms in accordance with anembodiment.

FIG. 4 is a side view of a component attached to a rotary member with asecondary attachment mechanism in accordance with an embodiment.

FIG. 5 is a side view of an engaged secondary attachment mechanism inaccordance with an embodiment.

FIG. 6 is an angled view of a rotary member with a t-slot socket inaccordance with an embodiment.

FIG. 7 is a side view of a component attached to a rotary member inaccordance with an embodiment.

FIG. 8 is an angled view of a rotary member with a t-slot socket and alatch in accordance with an embodiment.

FIG. 9 is a side view of a rotary member with a t-slot socket and alatch in accordance with an embodiment.

FIG. 10 is a side view of a component inserted into a rotary member inaccordance with an embodiment.

FIG. 11 is a view of components attached to a rotary member inaccordance with an embodiment.

FIG. 12 is a side view of a dove-tail shaped t-slot fastener head inaccordance with an embodiment.

FIG. 13 is a side view of a hook shaped t-slot fastener head inaccordance with an embodiment.

DETAILED DESCRIPTION

The foregoing summary, as well as the following detailed description ofcertain embodiments and claims, will be better understood when read inconjunction with the appended drawings. To the extent that the figuresillustrate diagrams of the functional blocks of various embodiments, thefunctional blocks are not necessarily indicative of the division betweenhardware circuitry. Thus, for example, one or more of the functionalblocks (e.g., processors, controllers or memories) may be implemented ina single piece of hardware (e.g., a general purpose signal processor orrandom access memory, hard disk, or the like) or multiple pieces ofhardware. It should be understood that the various embodiments are notlimited to the arrangements and instrumentality shown in the drawings.

As used herein, an element or step recited in the singular and proceededwith the word “a” or “an” should be understood as not excluding pluralof said elements or steps, unless such exclusion is explicitly stated.Furthermore, references to “one embodiment” are not intended to beinterpreted as excluding the existence of additional embodiments thatalso incorporate the recited features. Moreover, unless explicitlystated to the contrary, embodiments “comprising” or “having” an elementor a plurality of elements having a particular property may includeadditional such elements not having that property.

FIGS. 1 and 2 show a computed tomography (CT) imaging system 10including a gantry 12. Gantry 12 has a rotary member 13 an x-ray source14 that projects a beam of x-rays 16 toward a detector assembly 18 onthe opposite side of the rotary member 13. A main bearing may beutilized to attach the rotary member 13 to the stationary structure ofthe gantry 12. X-ray source 14 includes either a stationary target or arotating target. Detector assembly 18 is formed by a plurality ofdetectors 20 and data acquisition system (DAS) 22, and can include acollimator. The plurality of detectors 20 sense the projected x-raysthat pass through a subject 24, and DAS 22 converts the data to digitalsignals for subsequent processing. Each detector 20 produces an analogor digital electrical signal that represents the intensity of animpinging x-ray beam 16 and hence the attenuated beam as it passesthrough subject 24. During a scan to acquire x-ray projection data,rotary member 13 and the components mounted thereon can rotate about acenter of rotation.

Rotation of rotary member 13 and the operation of x-ray source 14 aregoverned by a control mechanism 26 of CT imaging system 10. Controlmechanism 26 can include an x-ray controller 28 and generator 30 thatprovides power and timing signals to x-ray source 14 and a gantry motorcontroller 32 that controls the rotational speed and position of rotarymember 13. An image reconstructor 34 receives sampled and digitizedx-ray data from DAS 22 and performs high speed image reconstruction. Thereconstructed image is output to a computer 36 which stores the image ina computer storage device 38.

Computer 36 also receives commands and scanning parameters from anoperator via operator console 40 that has some form of operatorinterface, such as a keyboard, mouse, touch sensitive controller, voiceactivated controller, or any other suitable input apparatus. Display 42allows the operator to observe the reconstructed image and other datafrom computer 36. The operator supplied commands and parameters are usedby computer 36 to provide control signals and information to DAS 22,x-ray controller 28, and gantry motor controller 32. In addition,computer 36 operates a table motor controller 44 which controls amotorized table 46 to position subject 24 and gantry 12. Particularly,motorized table 46 moves a subject 24 through a gantry opening 48, orbore, in whole or in part. A coordinate system 50 defines a patient orZ-axis 52 along which subject 24 is moved in and out of gantry opening48, a gantry circumferential or X-axis 54 along which detector assembly18 passes, and a Y-axis 56 that passes along a direction from a focalspot of x-ray tube 14 to detector assembly 18.

FIG. 3 shows one view of a rotary member 13 with a component 60 attachedthereto, according to one embodiment. Rotary member 13 may also bereferred to as a drum or disk. Component 60 can be an x-ray tube, highvoltage generator, heat exchanger, collimator, image detector, circuitboard chassis, balance weight, power supply, or other item to beattached to rotary member 13.

FIG. 3 shows primary attachment mechanism 62 and secondary attachmentmechanism 64 in normal operation conditions. Primary attachmentmechanism 62 may be bolts in one embodiment or other types of fasteningelements in alternative embodiments. FIG. 3 shows the primary attachmentmechanisms 62 attached to component 60 through slots 70. While theprimary attachment mechanisms 62 are shown at a perpendicular angle tothe rotary member 13, they can be set at alternative angles ororientations for fastening. In normal operation conditions as shown inFIG. 3, primary attachment mechanism 62 is engaged, thus pressed flushagainst rotary member 13, to prevent any pulling away of component 60due to centrifugal, gravitational, or other forces during operation ofthe CT imaging system 10. While FIG. 3 shows the sides of primaryattachment mechanism 62 as not flush against rotary member 13 in slot70, the sides can be flush in alternative embodiments. Slot 70 may havethreads to accept bolts or screws in one embodiment. While FIG. 3 showstwo primary attachment mechanisms 62, there can be any number in varyingembodiments.

Secondary attachment mechanism 64 is shown as a T-slot interface wherecomponent 60 has a T-slot fastener 68 that may be slid into T-slotsocket 66. T-slot fastener 68 includes a stem and a head. T-slot socket66 is integrated into the rotary member 13 in this embodiment. In analternative embodiment, T-slot socket 66 may be attached to rotarymember 13. T-slot fastener 68 is integrated into component 60 in thisembodiment. In an alternative embodiment, T-slot fastener 68 may beattached to component 60. Secondary attachment mechanism 64 is a safetydevice in one embodiment. In normal operation conditions shown in FIG.3, the secondary attachment mechanism 64 is not engaged and is bearingno component load, or weight. Thus, FIG. 3 shows no part of T-slotfastener 68 pressed flush against rotary member 13. Not bearing loadduring normal operation keeps it as strong as possible and reduces wear.While FIG. 3 shows two secondary attachment mechanisms 64, there can beany number in varying embodiments.

A T-slot interface can be described in one embodiment as a socket havinga base defining a recess bordered by a lip 78, and a fastener having anelongate stem portion and a head slidably insertable into the recess ofthe socket where it is retained by the lip 78 of the socket.

FIG. 4 shows a system where primary attachment mechanisms 62 are notinstalled and secondary attachment mechanisms 64 are engaged. Slots 70in rotary member 13 are empty in this example. This could be in asituation where the primary attachment mechanisms 62 were never put intoplace, fell out, were not torqued enough for secure fastening, were notthe right type of mechanism (wrong length, strength, etc.), arefatigued, are broken, or have had some other issue happen to them. Thiscan be considered a failure condition of a primary attachment mechanism62. In this situation the secondary attachment mechanism 64 takes theload. This is shown by the head of T-slot fastener 68 being flushagainst the top part T-slot socket 66 during rotation as the force pullscomponent 60 away from rotary member 13. Thus, the secondary attachmentmechanisms 64 protect component 60 from being ejected radially orotherwise from the rotary member 13. There also could be a situationwhere secondary attachment mechanism 64 only takes part of the load,such as when only some of the primary attachment mechanisms 62 areengaged or the primary attachment mechanisms 62 used are weak for somereason.

According to one embodiment, the gaps 84 within the secondary attachmentmechanism's T-slot interface allow for audible noise to be made when thesecondary attachment mechanism 64 is engaged. This can alert a nearbyhuman operator to notice that the gantry 12 is running in safety, orfailsafe, mode and not in normal mode so the operator can attend to thesafety issue. The system can be arranged so that the audible noises areonly during gantry 12 spin-up and spin-down or all the time duringoperation. According to an alternative embodiment, the gaps 84 are suchthat no audible noise can be heard.

The automatic engaging of the secondary attachment mechanism 64 is afailsafe. This can be desirable since a field engineer may not activatethe failsafe if it is manual. A manual installed failsafe is subject toincorrect installation itself. According to some embodiments, the systemcan automatically engage and requires no manual intervention to activatethe failsafe protection. Once the component 60 is in place, it will notbe thrown from rotary member 13 even without any primary attachmentmechanisms 62 installed.

FIG. 5 shows an engaged secondary attachment mechanism 64. The design ofthe secondary attachment mechanism 64 results in substantially evenforce distribution since load is being carried by both sides of theT-shape according to one embodiment. This increases strength andreliability for the secondary attachment mechanism 64.

FIG. 6 shows an angular view of rotary member 13 that includes one partof the secondary attachment mechanism 64, the T-slot socket 66. Acomponent 60 is first slid in the Z-direction 52 into the rotary member13. Then primary attachment mechanisms 62 can be installed through slots70. The slot 70 arrangement shown in FIG. 6 is exemplary. There can beone or more slots 70 and set in various arrangements in rotary member13.

FIG. 7 shows a view of secondary attachment mechanism 64 in analternative embodiment. The T-slot fastener 68 is integrated, orattached to, the rotary member 13. The T-slot socket 66 is integrated,or attached to, component 60.

FIGS. 8 and 9 show views of rotary member 13 that includes latch 72.Latch 72 depresses as a component 60 slides across it and into T-slotsocket 66. FIG. 8 shows an angled view. FIG. 9 shows a front view. Acomponent 60 with T-slot fastener 68 could slide into rotary member 13in the direction of the arrow 52 shown in the T-slot sockets 66 in FIG.8. After the component 60 has fully slid into T-slot socket 66, thelatch 72 rises to secure T-slot fastener 68 into place in the axial orZ-direction 52. Thus, the latch 72 retains the component 60 in therotary member 13 T-slot socket 66 in the axial or Z-direction 52. Thelatch 72 can also be referred to a Z-capture device, spring pin, orother names common to the art. It is a spring pin with a springmechanism in one example embodiment.

In the design of one embodiment, latch 72 is automatically engaged. Itcan be disengaged by manual user input or insertion of a component 60into the gantry's rotary member 13. Latch 72 cannot be left in adisengaged condition in this embodiment. When a user input to the latch72 is removed or the component 60 is fully inserted, the latch 72automatically returns to its engaged state. Latch 72 is further held inplace when rotational forces push outward in the radial direction.

FIG. 10 shows a side view of a component 60 inserted into rotary member13 using the secondary attachment mechanism 64 according to oneembodiment. The T-slot fastener head 74 has an angled edge 76 thatdepresses latch 72 as component 60 is slid into the secondary attachmentmechanism 64 of rotary member 13 along the Z-direction of the arrow inFIG. 10. After component 60 is fully inserted, latch 72 automaticallyrises to block the removal of component 60 without manual input. Anglededge 76 can also be known as a chamfer or ramp.

FIG. 11 shows additional embodiments of the system. Rotary member 13 hasthus far been shown with components 60 on the outside of the rotarymember 13. FIG. 11 shows components 60, of various shapes and sizes,attached or mounted to the inside of rotary member 13. Primaryattachment mechanisms 62 are still part of the system, but are not shownin the drawing. Secondary attachment mechanisms 64 are shown, sometimeswith one, two, or three per component 60 to show the flexibility of thesystem. In an alternative embodiment, components 60 can be placed onboth the inside and outside of rotary member 13.

FIG. 12 shows a side view of component 60 where the T-slot fastener head80 is dove-tail shaped, according to one embodiment. This is an exampleof another T-slot fastener and socket design that could be used.

FIG. 13 shows a side view of component 60 where the T-slot fastener head82 is hook shaped, according to one embodiment. This is an example ofanother T-slot fastener and socket design that could be used. OtherT-slot fastener and socket designs can be used as are common to the art.The receiving sockets can also be fashioned to best accept the specificfastener design.

The system disclosed provides useful safety mechanisms for gantries. Itprovides a secondary attachment mechanism that is not under load duringnormal operation. When a secondary attachment mechanism is engaged forsafety reasons due to an issue with primary attachment mechanism, thesystem can generate an audible noise for an operator to hear and addressthe issue. The system also provides additional safety capability byproviding an automatic latch to prevent any sliding of the secondaryattachment mechanism in the Z-direction.

It should be noted that the secondary attachment mechanism is a backupsafety mechanism in some embodiments, but can also be simply a secondattachment mechanism that also carries simultaneous load in otherembodiments.

It is to be understood that the above description is intended to beillustrative, and not restrictive. For example, the above-describedembodiments (and/or aspects thereof) may be used in combination witheach other. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the variousembodiments of the invention without departing from their scope. Whilethe dimensions and types of materials described herein are intended todefine the parameters of the various embodiments of the invention, theembodiments are by no means limiting and are exemplary embodiments. Manyother embodiments will be apparent to those of skill in the art uponreviewing the above description. The scope of the various embodiments ofthe invention should, therefore, be determined with reference to theappended claims, along with the full scope of equivalents to which suchclaims are entitled.

In the appended claims, the terms “including” and “in which” are used asthe plain-English equivalents of the respective terms “comprising” and“wherein.” Moreover, in the following claims, the terms “first,”“second,” and “third,” etc. are used merely as labels, and are notintended to impose numerical requirements on their objects. Further, thelimitations of the following claims are not written inmeans-plus-function format and are not intended to be interpreted basedon 35 U.S.C. § 112, sixth paragraph, unless and until such claimlimitations expressly use the phrase “means for” followed by a statementof function void of further structure.

This written description uses examples to disclose the variousembodiments of the invention, including the best mode, and also toenable any person skilled in the art to practice the various embodimentsof the invention, including making and using any devices or systems andperforming any incorporated methods. The patentable scope of the variousembodiments of the invention is defined by the claims, and may includeother examples that occur to those skilled in the art. Such otherexamples are intended to be within the scope of the claims if theexamples have structural elements that do not differ from the literallanguage of the claims, or if the examples include equivalent structuralelements with insubstantial differences from the literal languages ofthe claims.

What is claimed is:
 1. A gantry, comprising: a stationary supportstructure; a rotary member, attached to the stationary supportstructure, comprising an inside opening for insertion of a subject; aprimary attachment mechanism; a secondary attachment mechanismcomprising a T-slot interface; and a component; wherein the componentcan be attached to an outside of the rotary member by the primaryattachment mechanism; and wherein the component can be attached to theoutside of the rotary member by the secondary attachment mechanism. 2.The gantry of claim 1, wherein: the primary attachment mechanismcomprises one or more bolts.
 3. The gantry of claim 1, wherein theT-slot interface further comprises: a socket comprising a lip and a basedefining a recess bordered by the lip, the socket securable to a firstmember; a fastener comprising an elongate stem portion securable to asecond member and a head slidably insertable into the recess of thesocket where the fastener is retained by the lip of the socket; andwherein the first member is the rotary member and the second member isthe component, or the first member is the component and the secondmember is the rotary member.
 4. The gantry of claim 3, wherein: the headof the fastener is shaped in a T-shape.
 5. The gantry of claim 3,wherein: the head of the fastener is shaped in a dove-tail shape.
 6. Thegantry of claim 3, wherein: the head of the fastener is shaped in a hookshape.
 7. The gantry of claim 1, the T-slot interface furthercomprising: a T-slot socket integrated into the rotary member; and aT-slot fastener integrated into the component.
 8. The gantry of claim 1,the T-slot interface further comprising: a T-slot fastener; a T-slotsocket; and a latch for securing the T-slot fastener in place to preventaxial movement of the T-slot fastener from the T-slot socket.
 9. Thegantry of claim 8, wherein: the T-slot fastener includes an angled edgeon an insertion side; and the angled edge depresses the latch as theT-slot fastener is slid into the T-slot socket.
 10. The gantry of claim8, wherein the latch comprises a spring pin.
 11. The gantry of claim 1,wherein: during rotation of the rotary member, the secondary attachmentmechanism does not support a weight of the component if the primaryattachment mechanism is engaged.
 12. The gantry of claim 1, wherein:during rotation of the rotary member, if the primary attachmentmechanism is not engaged, the secondary attachment mechanism supports aweight of the component.
 13. The gantry of claim 12, wherein: the T-slotinterface includes gaps that generate a human-audible noise duringmovement of the gantry.
 14. The gantry of claim 1, wherein: duringrotation of the rotary member, if the primary attachment mechanism ispartially engaged, the secondary attachment mechanism supports aremaining weight of the component.
 15. The gantry of claim 1, wherein:the component is an x-ray tube, a high voltage generator, a heatexchanger, a collimator, an image detector, a circuit board chassis, abalance weight, or a power supply.
 16. An annular structure, comprising:a central opening; a primary attachment mechanism; at least one slot toaccept the primary attachment mechanism; a secondary attachmentmechanism comprising at least one socket; the at least one socketcomprising a lip and a base defining a recess bordered by the lip; andwherein the primary attachment mechanism and the secondary attachmentmechanism can be used to attach a component and the secondary attachmentmechanism does not support a weight of the component if the primaryattachment mechanism is engaged.
 17. The annular structure of claim 16,the T-slot interface further comprising: a T-slot fastener; a T-slotsocket: and a latch for securing the T-slot fastener in place to preventaxial movement of the T-slot fastener from the T-slot socket.
 18. Theannular structure of claim 17, wherein: the T-slot fastener includes anangled edge on an insertion side; and the angled edge depresses thelatch as the T-slot fastener is slid into the T-slot socket.
 19. Theannular structure of claim 17, wherein: the latch comprises a springpin.